Prevalence and genetic diversity of gastroenteritis viruses in hospitalized children

Summary of the Study

Diarrheal diseases remain a major cause of mortality among children in low- and middle income countries, with viruses being the leading cause of acute gastroenteritis (AGE), particularly Rotavirus A (RVA). RVA alone accounts for approximately 40% of global diarrheal deaths in children under five and exhibits extensive genetic diversity. Other important viral agents of AGE include norovirus, sapovirus, enteric adenovirus, and astrovirus. In India, rotavirus is responsible for 35–40% of AGE cases in young children and imposes a substantial economic burden, while data on non-rotavirus viral gastroenteritis remain limited. Following the introduction of rotavirus vaccination, a decline in RVA infections and a relative increase in non-rotavirus AGE has been observed. Against this background, a hospital-based study was conducted in Pune, Maharashtra, enrolling 308 hospitalized children with AGE between May 2017 and December 2019 to assess the prevalence, clinical characteristics, and genotypes of four major gastroenteritis viruses and to compare viral etiology between rotavirus-vaccinated and unvaccinated children, providing baseline data from the pre-vaccination period for future comparisons. Most affected children (79%) were under two years of age. Four viruses accounted for 54% of cases, with Rotavirus A being the most prevalent (30.5%), followed by norovirus (14.3%), adenovirus (8.4%), and astrovirus (5.5%). Co-infections were associated with significantly greater disease severity. Genotyping showed dominance of RVA G3P[8], norovirus GII.4 Sydney [P16], adenovirus type 41, and astrovirus type 1. The study observed nearly equal prevalence of rotavirus and non-rotavirus infections and noted that 46% of cases had no identified viral etiology. These findings underscore the need for expanded surveillance of non-rotavirus pathogens, especially following the introduction of rotavirus vaccination in India. This work was supported by the Indian Council of Medical Research, National Institute of Virology (ICMR-NIV) Pune, India.